alpha-Endosulfine is a conserved protein required for oocyte meiotic maturation in Drosophila.
Meiosis is coupled to gamete development and must be well regulated to prevent aneuploidy. During meiotic maturation, Drosophila oocytes progress from prophase I to metaphase I. The molecular factors controlling meiotic maturation timing, however, are poorly understood. We show that Drosophila alpha-endosulfine (endos) plays a key role in this process. endos mutant oocytes have a prolonged prophase I and fail to progress to metaphase I. This phenotype is similar to that of mutants of cdc2 (synonymous with cdk1) and of twine, the meiotic homolog of cdc25, which is required for Cdk1 activation. We found that Twine and Polo kinase levels are reduced in endos mutants, and identified Early girl (Elgi), a predicted E3 ubiquitin ligase, as a strong Endos-binding protein. In elgi mutant oocytes, the transition into metaphase I occurs prematurely, but Polo and Twine levels are unaffected. These results suggest that Endos controls meiotic maturation by regulating Twine and Polo levels, and, independently, by antagonizing Elgi. Finally, germline-specific expression of the human alpha-endosulfine ENSA rescues the endos mutant meiotic defects and infertility, and alpha-endosulfine is expressed in mouse oocytes, suggesting potential conservation of its meiotic function.
Von Stetina
Jessica R
JR
Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA.
Tranguch
Susanne
S
Dey
Sudhansu K
SK
Lee
Laura A
LA
Cha
Byeong
B
Drummond-Barbosa
Daniela
D
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D005075:Biological Evolution; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002454:Cell Differentiation; D017124:Conserved Sequence; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008540:Meiosis; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009685:Nuclear Envelope; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D016415:Sequence Alignment; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D029721:Drosophila Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; C075663:endosulfine; C075186:twe protein, Drosophila; D044767:Ubiquitin-Protein Ligases; C072004:polo protein, Drosophila; D017346:Protein Serine-Threonine Kinases; D016203:CDC2 Protein Kinase